Shaft for a writing instrument



FIG. 1 is a front elevational view of a shaft for a writing instrument showing my new design with the grip members in a first arrangement;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a side view thereof illustrating the use thereof in a writing instrument;

FIG. 8 is a front view thereof with the grip members in a second arrangement;

FIG. 9 is a front view thereof with the grip members in a third arrangement; and,

FIG. 10 is a front view thereof with the grip members in a fourth arrangement.

The broken line showing of a writing instrument in FIG. 7 is environmental only and forms no part of the claimed design. 

The ornamental design for a shaft for a writing instrument, as shown and described. 